EP 0199218 A2 19861029 - Evoked potential autorefractometry system.
Title (en)
Evoked potential autorefractometry system.
Title (de)
Refraktionsmessung mittels evozierter Potentiale.
Title (fr)
Système de mesure de la réfraction à l'aide de potentiels évoqués.
Publication
Application
Priority
US 72703285 A 19850425
Abstract (en)
@ An evoked potential autorefractometry system includes a computer driving an alternating checkerboard mirror stimulus to project a stimulus pattern directly to a patient through a continuously variable focus lens controlled by the computer and maintaining a constant image size on the patient's retina. The evoked potentials produced by the patient are amplified and asynchronously filtered both in an analog and digital fashion to allow peak to peak detection of the evoked potentials to determine amplitude. The digital filter includes a 255 point running sum. The peak to peak amplitudes are asynchronously digitally filtered using a 16 point running sum to produce an amplitude measure of the evoked potentials. The lens is swept rapidly from one extreme of focus to the other extreme in relatively large steps to determine the area in which the peak amplitude occurs. The lens is then swept in smaller and smaller range sweeps using smaller and smaller steps around the peak amplitude until the peak in the amplitude is pinpointed within a desired diopter at which point the lens position is printed out on the printer as the patient's prescription.
IPC 1-7
IPC 8 full level
A61B 3/028 (2006.01); A61B 3/10 (2006.01); A61B 3/103 (2006.01); A61B 5/04 (2006.01); A61B 5/0408 (2006.01); A61B 5/0476 (2006.01); A61B 5/0484 (2006.01)
CPC (source: EP KR US)
A61B 3/103 (2013.01 - EP US); A61B 3/12 (2013.01 - KR); A61B 5/282 (2021.01 - EP US); A61B 5/369 (2021.01 - EP); A61B 5/377 (2021.01 - EP US); A61B 5/6814 (2013.01 - EP US); A61B 2562/222 (2013.01 - EP US)
Designated contracting state (EPC)
BE CH DE FR GB IT LI NL SE
DOCDB simple family (publication)
EP 0199218 A2 19861029; EP 0199218 A3 19880629; CN 1008685 B 19900711; CN 86102827 A 19861105; ES 554292 A0 19870716; ES 8707094 A1 19870716; JP H0580204 B2 19931108; JP S61249433 A 19861106; KR 860007911 A 19861110; US 4697598 A 19871006
DOCDB simple family (application)
EP 86104990 A 19860411; CN 86102827 A 19860424; ES 554292 A 19860423; JP 9658686 A 19860424; KR 860003102 A 19860422; US 72703285 A 19850425